Wire line tester



April 10, 1956 E. W. BAGNELI.

WIRE LINE TESTER 5 Sheets-Sheet l Filed May 5. 1952 INVENTOR DGFIQ LU.BQGNLL MMM m'roQNeys April 10, 1956 E. w. BAGNELL WIRE LINE TESTER 5Sheets-Sheet 2 Filed May 3. 1952 INVENTOR. DECIR LU. B CIGNELL P12/Q.7a.

nTToQnva April 10, 1956 E. w. BAGNELL WIRE LINE TESTER 5 Sheets-Sheet 5s\ 1m l I INVENTOR DGQQ LU. BQGNLLL Filed May 3. 1952 MMM n'rToQNealApril 10, 1956 E. w. BAGNELL WIRE LINE TESTER 5 Sheets-Sheet 4 Filed May5, 1952 5 i may..

wl gai- S lll INVEN DGCIQ LU. BGG

April 10, 1956 E. W. BAGNELI.

WIRE LINE TESTER 5 Sheets-Sheet 5 Filed May 3, 1952 INVENTR. DGQQ LU.BQGNLL.

United States Patent O gmx WIRE LINE TESTER Edgar W. Bagnell, Glendaie,Calif., assignor, by mestre assignments, to Johnston Testers, lne.,Houston, Tex., a corporation of Texas Application May 3, 1952, SerialNo. 285,981

16 Ciaims. (Cl. 16e- 147) This invention relates to oil well tools andparticularly to a formation uid testing tool. It is necessary in taking2,741,313 Patented Apr. 10, 1956 housings, and the like, -to bedescribed hereinafter, and

. which is adapted to be suspended from the lower end of housing 23,which is urged toward the upper end of a sample of formation fluid withthe usual tool to set packers, open and close several valves, andoperate various other parts. Heretofore, these operations were performedby suspending the tool from a drill string and rotating and/or raisingor lowering the drill string to cause corresponding rotary and linearmovements of parts of the tool as well as imposing part of the weight ofthe drill string on other parts to set packers,etc. Use of a string ofpipe is not only expensive but time consuming since the section must beassembled when running in a well and then disassembled when running outof the hereinafter.

take a sample of the formation uid, thereby eliminating the expense anddelay accompanying the use of a string of pipe. Another object of thepresent invention is to provide a formation testing tool as abovedescribed which utilizes the well fluid pressure to cause expansion of apair of packers, and which packers can be collapsed by a pressurereleasing arrangement actuated by an upward pullon the wire line.

Various other objects will be apparent from the following descriptiontaken in connection with the accompanying drawings wherein:

Figs. la, 1b and lc illustrate successive sectional views of an oil welltool embodying the concepts of the present invention;

Figs. 2a, 2b and 2c are similar to views la, lb and lc,

respectively, but show the parts in a subsequent stage of operation;

Fig. 3 is an enlarged fragmentary View more clearly showing theconstruction of the packers and the centrai packer head between saidpackers;

Fig. 4 is a still further enlarged view in section showing the internalconstruction of the central packer head;

Fig. 5 is a longitudinal sectional view of the valve locking arrangementwith the parts disposed in running-in condition;

Fig. 6 is a View similar to Fig. 5 but with the parts disposed with thetool in packed condition;

Fig. 7 is a horizontal sectional view taken along line 7-7 of Fig. 6;Fig. 8 is a view similar to Fig. 6 but showing a subsequent condition ofthe other parts, namely, when the device is in condition for running outof the well;

Fig. 9 is a View similar to Fig. 4 but showing the formation uid valvein opened condition;

Fig'. l0 is a view similar to Figs. la and 2a but showing the parts incondition for running out of the well.

Referring to the accompanying drawings, wherein similar referencecharacters designate similarparts throughout, the oil well tooldisclosed includes a composite tool body,

generally entitled 15, made up of various subs, cylinders,

composite tool body 15 by a compression spring 25. Spring 25 surroundsan upwardly extending stem 27 on the upper end of body 15 and iscontained between a nut 29 on the upper end of stem 27 and a ange 31formed on the lower end of spring housing 23. Surrounding stem 27 is astop sleeve 33 adapted to abut against nut 29 when the tool is suspendedfrom wire line 17 because of the compression of spring 25 by the weightof the tool.

Included in composite tool body 15 is a valve sub 41 threadedlyconnected at its lower and upper ends to other housing parts to bedescribed hereinafter. Valve subA 41 has formed therein well uid inletpassages 43 adapted to communicate with a central passage 45 which inturn communicates with the upper end of a low pressure piston 47, thelatter being slidably received within a low pressure cylinder 49threadedly secured to lower end of valve Sub 41. Passage of Well fluidthrough passages 43 into central passage 45 is controlled by a packersetting slide valve 51, said valve being a part of a compound valvemember generally entitled 53 to be described in detail As shown in Fig.lb, slide valve 51 is disposed in a position to close ports 43 andprevent well uid from being effective on lower pressure piston 47.Throughout the specication, the term well fluid will mean Lhe uid foundin the well Whether it be drilling fluid, water, ora combination ofvarious fluids, whereas the term formation fluid or connate iluid willrefer to the sample iiuid which is to be taken.

Low pressure piston 47 is formed integrally with a high pressure piston54, the latter fitting within a high pressure cylinder 55 secured to thelower end of the low pressure cylinder 49. Suitable O rings are providedon the exterior of low pressure piston 47 and on the interior of highpressure cylinder 55 to provide a sealing engagement between thecylinders and the pistons. When valve 51 is moved to its openedposition, and well iiuid becomes eiective against low pressure piston47, a body of hydraulic fluid, contained in tool body 15 and generallyentitled 57, is forced downwardly through passages 59 formed in a toppacker head 61 and into an upper tubular mandrel 63. Mounted on uppermandrel 63 is an upper expansible packer, generally entitled 65, adaptedto be expanded by the hydraulic fluid into engagement with the walls ofthe well bore to form a seal therewith. Tubular mandrel 63 has suitableports 67 for ingress and egress of hydraulic fluid therethrough to causeexpansion and allow contraction of expansible packer 65.

Top packer head 61 is secured to the lower end of high pressure cylinder55 (see Fig. lb) and to the upper end of mandrel 63. The lower end ofmandrel 63 is threadedly secured to a central packer head 69. There isprovided a lower packer mandrel 71 secured at its upper end to centralpacker head 69 and at its lower end to a bottom packer head 73, saidmandrel carrying therearound a lower expansible packer, generallyentitled 75. Tubular mandrel 71 is also provided with lateral ports 77for egress of hydraulic iluid outwardly another so that when highpressure piston 54 is forced downwardly by the effects of Well Huidpressure on low pressure piston 47, hydraulic uid under a pressuregreater than that of the well fluid (to a degree proportional to theratio of the diameters of the pistons) will be forced through passages59 in the top packer head 61 and pass through mandrel ports 67 and 77and cause expansion of packers 65 and 75 so that the packers will form aseal with the walls of the well bore and, therefore, provide an annularformation uid space around the enterior of central head 69 and betweenthe packers.

Central packer head 69 has formation fluid passages 81 formed thereinadapted to communicate with a formation uid test tube 33 through a testvalve to be described more in detail hereinafter, said valve beingopened by the pressureY of the hydraulic duid to allow connate uid toflow through passageways S1 down through test tube 83 and into a tailpipe $5 which forms a formation or test chamber for the reception of thetest sample.

Fromthe above description it is apparent that when packer setting valve51 is opened, well iiuid pressure will be effective to indirectly canseexpansion of packers 65 and 75, to set the packers in the well bore, andalso to indirectly cause opening of the test valve, in a manner to bedescribed hereinafter, to allow formation iuid'to ow down into the tailpipe 35 for entrapment of a sample. Y Each of packers 65 and 75 is ofsimilar construction and'therefore the details of only one packer'willbe described. As best shown in Fig. 3, each packer comprises a hollowelongated resilient body 91 tightly tting at its ends on itsrmandrel andbeing restrained against end bulging by a plurality of fabric and rubberdome-shaped heads 93 fitted onto the mandrel of the particular packer inquestion and serving to' retain the packers against undue longitudinalexpansion. The dome-shaped heads are adapted to be expanded axially intoengagement with the walls of a well bore and against frusto-conicalsurfaces 95 formed on the packer heads, said surfaces serving to supportthe dome-shaped head after a predetermined amount of distortion thereof.Within each packer is an annular core 97 fitting onto the associatedmandrel and being interiorly uted to permit fluid passage between themandrel and core to the opposite ends of the core, and around the endsto expand the packer. The packers during their expansion move away fromtheir respective cores. VEach packer is thick at its medial portion andthin at its ends so thatthe ends rst expand and force heads 93 intoengagement with the walls of the well bore. The low pressure and thehigh pressure pistons 4'7 and 54`have a central air chamber 9S formedtherein adapted to communicate through air ducts 93a with an annular airchamber 99 provided between the exterior of high pressure piston 54 andtheeinterior of low pressure cylinder 49. There is a plug 1130 closingthe upper end of air chamber 98. When low pressure piston 4.7 is forceddownwardly, part of the air within the annular chamber 99 is forcedthrough ducts 98a into air chamber 98 so that the air resistance tomovement of piston 47 is reduced to an unobjectionable value.V

Packer setting valve 51 as previously mentioned forms a part of acompound valve member 53, the other valve of said compound valve memberto be described hereinafter, At present, it suiiices to say that thecompound valveA member is in a form of a rod having the lower endprovided with a bore adapted to communicate with passages 43 by rports101. Compound valve member 53 is connected to a connector rod 103 whichslidably extends through a lock mechanism 105 to be presently describedand into the lower end of a piston rod 197. Piston rod 107 is connectedto a piston 169, the latter fitting within a piston housing 111. Piston109 is adapted to be driven downwardly, thereby moving packer settingvalve 51 to a position where the ports 101 thereof register with thepassages 43, by means of the detonation cartridges 113 receiving sockets137 formed therein.

carried by a cartridge carrier 115 mounted in the upper end of pistonhousing 11. For causing detonation of the cartridges 113, there isprovided a clock and battery arrangement 117 wired to the cartridges byleads 119.VV The clock mechanism is such that a predetermined time afterthe tool has been lowered into the well, the clock mechanism will closea switch supplying current from the battery to cartridges 113 to cause adetonation thereof, to drive piston 109 downwardly and, therefore, drivepacker setting valve 51 downwardly.

The clock and battery mechanism 117 and therefore compound valve 53 isspring urged upwardly by Van expansion spring 121. There is a releasingmandrel 123 extending from the upper end of the clock and batterymechanism 117 and through stem 27 Vand sub 22. Sub 22 contains a pair ofspring pressed detents 125 adapted to snap into a groove 127 formed inreleasing mandrel 123 to lock the mandrel to sub 22. Groove 127 isdisposed beneath the detents, as shown in Fig. la, when the tool isbeing run into the well. The function of this releasing mandrel will beexplained hereinafter.

It is apparent from the above description that after cartridges 113 havebeen tired it is necessary to hold packer setting valve 51 in registrywith passages 43 against the resistance of spring 121. To perform thisfunction, lock mechanism 105 previously mentionedis provided. Lockmechanism 105 isV best shown in Figs. 5 through 8 and is containedwithin a lock sub or housing 131, which is secured to the lower end Vofpiston housing 111 and to the upper end of a vacant housing 133, whichin turn is secured at its lower end to the upper end of valve sub 41.The lock mechanism as shown in the above Figures includes piston rod 167and connector rod 103, said piston rod having a reduced lower endslidably tting within a bore provided in the upper end of connector rod103, said reduced portion 135 having ball Sockets 137 are disposedas'the parts are depicted in Fig. 5 in registry with a pair of ports 139formed in the upper end of connector rod 103. Surrounding the upper endof connector rod 103 is a locked housing 141 having a pair of lockingballs 143 received within guides 145 formed in the locked housing.Locking balls 143 are urged mwardly by a circular coil tension spring147. Y

It is apparent from the above construction that when the piston rod 107is driven downwardly by the detonationrof cartridges 113, ports 139 andysockets 137 are brought into registry with balls 143, said ballssnapping into the ports and sockets to positively lock the connector rodagainst upward movement, and, therefore, locklng packer setting valve 51in a position with its ports 101 in lateral registry with well uid inletpassages 43. Further operation of the locking mechanism will beexplained hereinafter. For the present it is suicient to say thatlocking balls 143 only releasably hold .piston rod 107 against upwardmovement, and that said rod can be pulled upwardly, to the positionshown in Fig. 8, to cam the locking balls 143 outwardly to release theconnector rod for upward movement under the influence of a force to bedescribed, said rod serving to further outwardly cam the locking balls.

A summary of the operations up to this point shows that after the toolhas been run into the well, the clock mechanism, which has been set atthe surface,` will close a switch at a predetermined time after the toothas been lowered into the well to supply electric current to cartridges113, to cause detonation thereof to drive piston 199 downwardly and movepacker setting valve 51 to open position. Well fluid under pressure willflow into the tool and be effective against low pressure piston 47 toforce high pressure piston 51 downwardly, the latternamed piston forcinghydraulic fluid 57 through tubular mandrels 63 and 71 from whence theiiuid can ow out throughv ports 67 and 77 and cause expansion of packers65 and 75. The locking mechanism 165 will be eective to lock valve 51 inits open position.

Setting of the packers in the well will relieve the weight of the toolfrom spring 25, said spring being effective, upon a slight slackening ofline 17 to force sleeve 23 and therefore sub 22 downwardly to allowdetents 125 to snap into groove 127 of releasing mandrel 123 (see Fig.2a). Detents 125 are not inserted into place until the rest of the toolis suspended from wire line 17 to compress spring 25 and bring thedetentv passages above groove 127 in releasing mandrel 123. Then, thedetents are inserted into sub 22.

The construction of central packer head 69 and the construction andoperation of the test valve, previously mentioned, will now beexplained.V As previously indicated, central packer head 69 and thelower end of mandrel 63 are so formed that hydraulic uid can ow fromtubular mandrel 63 into tubular mandrel 71. As best shown in Figs. 3 and4, the lower end of upper tubular mandrel 63 is solid and formed withpassages 151 communicating with a passage 153 formed in a nipple 155,the latter being secured to the lower end of tubular mandrel 63. Nipple155 rests on a nut 157 threaded into the upper end of a plug 159 whichis disposed within a central bore provided in central packer head 69.Fluid flowing through passage 153 ilows into passages 161 formed in nut157, plug 159 and central packer head 69, the lower end of passages 161communicating with the interior of lower mandrel 71.

Test tube 83 previously mentioned lits within the lower end of plug 159as shown in Fig. 4, said plug being centrally bored to receive a testvalve 163 slidably tting therewithin. Valve 163 is provided withsuitable O rings for sealing engagement with plug 159. Test valve 163 isspring urged upwardly by an expansion spring 165 and is provided with acentral bore terminating in lateral ports 167 which are adapted to bebrought into registry with a cavity 168 formed in plug 159, said cavitycom` municating with previously mentioned formation test ports 81(compare Figs. lc, 3 and 4). When ports 167 are disposed within cavity168, formation or test uid can ilow in through passages 81, throughports 167, down through test tube 83 and into tail pipe 85 where thesample is collected.

Limiting upward movement of test valve 163 is a nipple 171 threaded intoplug 159, said nipple having a bleed passageway or orifice 173 extendingtherethrough for applying hydraulic fluid to the top of test valve 163.A resilient sleeve 175 covers lateral ports 177 provided in nipple 171.Orice 173 is of such size that the hydraulic fluid can only bleed slowlytherethrough so that packers 65 and 75 are fully expanded by the timethat suicient fluid has bled through nipple 171 to cause test valve 163to move into a position where the ports thereof are disposed withincavity 163. Therefore, the packers are set before test tiuid is allowedto pass down through test tube 83.

It is very desirous and in some operations necessary that the weight ofdrilling mud or well fluid not be im; posed on the upper packer 65 and,therefore, an equalizing passageway is provided in the tool so as toby-pass the packers and allow the well fluid below and above the wellpackers to equalize pressure during a test operation. Referring to Figs.1c and 3, upper top packer head 61 has lateral passages 181 formedtherein in communication with the upper end of an upper equalizing tube132i, which is disposed within upper tubular mandrel`63 and has itslower end sealingly held within the lower solid end of said mandrel.Also formed within lower solid end of mandrel 63 are equalizing passages135 communieating withV passages 156 formed in central packer head 169,passages 186, as best shown in Fig. 4, communicating with the interiorof a lower equalizing tube 139, which is fixed at its upper end to plug159 and at its lower end sealingly engages the interior of a reducedbore 191 formed in the lower end of tubular' mandrel 71. In com-fmunication' with equalizing tube 189 are lateral equalizing passages 193formed in bottom packer head 73. It is apparent from the abovepassageway construction that` well uid pressure can be equalized aboveand below packers' 65 and 75 at all times during testing operationthereby not imposing the weight of the drilling mud on the upper packer.The equalizing passages also insure that the mud pressure below thepacker will be main` tained even though some mud is lost during atesting operation.

Reference is now made to several later steps in the operation of thetool. After sumcient time has elapsed to ensure the entrapment of anadequate sample, it is desired to remove the wire line tester from thewell. To accomplish this, an upper pull on wire line 17 is e'tected tocompress spring 25 and raise orlift releasing mandrel 123 (which is notlocked to sub 22) upwardly to cam locking ball 143 out of sockets 1737and raise stern 135 from the position shown in Fig. `6 to the positionshown in Fig. S. The well uid pressure constantly urges rod 193 upwardlyso that it follows the upward movement of stem 135, and further camsballs 143 outwardly to the positions shown in Fig. 8.

Compound valve 53 is carried upwardly by the upward movement of rod 163to register lower ports 20G of a release valve 261 with passages V203formed in valve sub 41, passages 293 communicating with the upper end oflow pressure piston 47. Release valve 291 forms the second valve ofcompound valve member 573, valve 201 being formed by the provision of abore 204 in the upper end of valve member 53, lateral ports 200 beingadapted to communicate the bore with passages- 203 when the compoundvalve member 53 is raised from the position shown in Fig. 2b to theposition shown in Fig. lb. There are upper lateral ports 257communicating the interior of the bore 294 with the interior of vacanthousing 133.

It is apparent from the above described parts that upon an upward pullon wire line 17, valve 51 is released from its locked position and underthe inuence of the well pressure moves upwardly to its closed positionto align the ports 260 of release valve 291 with passageways 203 toallow the trapped well uid under pressure in low pressure cylinder 49 topass upwardly into the vacant housing 133. Low and high pressure pistonsi7 and 53 are then free to move upwardly, under the influence of thepressure of the hydraulic uid, to their initial positions, therebyallowing collapse of packers 65 and 75. When the pressure of thehydraulic Huid is reduced bythe above operation, spring of test valve163 causes the valve to move upwardly from the position shown in Fig. 9to the position shown in Fig. 4 to close the test valve and therebyentrap the test sample within tail pipe S5.

When going into the well, the high pressure in the space above and onthe outside of sleeve causes ports 177 to be closed, and thereforehydraulic iluid must pass only throughoritice 173. When'the packers arereleased, the low pressure on the outside of sleeve 175 permits fluid toescape through ports 177, thereby allowing valve 163V to close quicklyunder influence of spring 165.

T ail pipe 35 may contain a recorder if desired to shov'. the shut-inpressure when the tail pipe is completely filled.

By the present invention an oil well formation uid testing tool has beenprovided which can be suspended in a well by a wir-e line and operatedto successfullyi set a pair of'packers and then take a sample, andthereafter the packers can be collapsed and the sample entrapped. ltwill be appreciated that by providing a low pressure piston and a highpressure piston, the hydraulic fluid acted on by the high pressurepiston will be under a pressure sufficiently higher than tliatof thewell uid to hold the packersv against the well bore tocr'eate aneffective seal. After the tool is brought to the surface the vtestparting from the spirit of the invention as dened in the appendedclaims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

l. An oil well formation fluid tester comprising a tool body havingspaced expansible packers thereon, said tool body having a samplechamber formed therein, a irst passage connecting the chamber with theexterior of the tool body at a point betwen the packers, a first valvein said tirst passage for controlling the iiow of formation iiuidtherethrough, hydraulic means operatively connected to said packers andsaid first valve and adapted to be actuated by the hydrostatic pressureof the iiuid in the well bore to expand said packers and subsequentlyopen said first valve, a second passage connecting said hydraulic meansand the exterior of said tool body above said pack-V ers, a second valvefor controlling the ow of well uid through said second passage, meansfor opening said second valve to permit the hydrostatic pressure of theuid in the well bore to actuate said hydraulic means, a

Vsecond sealed chamber in said tool body, a third passage connectingsaid second chamber with said hydraulic means, a third valve in saidthird passage, and meansv connected to said second and t .ird valves forsubsequently closing said second valve and then opening said third valveto permit the well uid trapped in said hydraulic means by the closing ofsaid second valve to enter said second chamber, thus permitting saidfirst valve to close and subsequently said packers to collapse.

2. In'combination, wire line, tool body connected to the lower Vend ofthe wire line and adapted to be lowered into a well by said line, saidbody having spaced expansiblerpaclcers thereon, said tool body having asample chamber formed therein, a first passage connecting the chamberwith the exterior of the tool body at a point between the packers, aiirst valve in said first passage for controlling the flow of formationiluid therethrough, hydraulic means operatively connected to saidpackers and said first valve and adapted to be actuated bythehydrostatic pressure of the fluid in the well bore to expand saidpackers and subsequently open said first valve, a second passageconnecting said hydraulic means and the exterior of said tool body abovesaid packers, a second valve for controlling the iiow of Well iiuidthrough said second passage, and means for opening said second valve topermit the hydrostaticV pressureof the iiuid in the well bore to actuatesaid hydraulic means. Y

3. ln combination, a wire line, a tool body connected to the lower endof the wire line and adapted to be lowered into a well by said line,said body having spaced Y expansible packers thereon, said tool bodyhaving a sample chamber formed therein, a iirst passage connecting Vthechamber with the exterior of the tool body at a point draulic meansoperatively connected to said packers and said iirst valveland adaptedto be actuated by the hydrostatic pressure of the fluid in the well boreto expand said packers and subsequently open said first valve, a secondpassage connecting said Yhydraulic means and the exterior of said toolbody above said packers, a second valve for controlling lthe ow of wellliuid through said second passage, means for opening said second valveto permit the hydrostatic pressure ofthe iiuid in the well bore toactnate said hydraulic means, a second sealed chamber in said tool body,a third passage connecting saidsecond chamber with saidhydraulic means,a third valve in said third passage, and meansA connected to said secondand third valves for subsequently closing said second valve and thenopening said third valve to permit the well tluid trapped l packers tocollapse.

in said hydraulic means by the closingof said second valve to enter saidsecond chamber, thus permitting said first valve to'close andsubsequently said packers to collapse.

4. An oil well formation fluid tester comprising a tool body havingspaced expansible packers thereon, a body of hydraulic uid in said toolbody, a conduit connecting said body of iiuid with the interior of saidpackers, said tool body having a sample chamber formed therein, a firstpassage connecting the chamber with the exterior of the tool body at apoint between the packers, a first valve in said iirst passage forcontrolling the flow of formation fluid therethrough, hydraulic meansoperatively connected to said packers and said first valve and adaptedto be actuated by the hydrostatic pressure of the huid in the well boreto expand said packers and subsequently open said first valve, saidhydraulic means comprising a low pressure piston adapted to be actuatedby well :duid pressure, a high pressure piston connected to said lowpressure piston for actuation thereby, said high pressure pistou beingin communication with said body of Vhydraulic uid whereby a higherpressure than existing in the well uid is created to expand the packersag instrthe walls of the well bore, a second passage in said tool bodyproviding communication between said low pressure piston and theexterior or" said tool body above said packers, a second valve forcontrolling the iiow of well iiuidrthrough said second passage, andmeans for opening second valve to permit the hydrostatic pressure or theiiuid in the well Vbore to actuate said hydraulic means.

5. An oiltwell formation huid tester comprising a tool body havingspaced expansible packers thereon, a body of hydraulic tiuid in saidtool body, a conduit connecting said body of fluid with the interior ofsaid packers, said tool body having a sample chamber formed therein, afirst passage connecting the chamber with the exterior of the tool bodyat a point between the packers, a first valve in said first passage forcontrolling the `)flow of formation fluid therethrough, hydraulic meansoperatively connected to said packers and said iirst valve and adaptedto be actuated by the hydrostatic pressure of the fluid in the well boreto expand said packers and subsequently open said iirst valve, saidhydraulic means comprising a low pressure piston adapted to be actuatedby well iiuid pressure, a high pressure piston connected to said lowpressure piston for actuation thereby, said high pressure piston beingin communication with said body of hydraulic fluid whereby a higherpressure than existing in the well fluid is created to expand thepackers against the walls of the well bore, a second passage in saidtool body providing communication between said low pressure piston andthe exterior of said tool body above said packers, a second valve forcontrolling the iiow of well iiuid through said second passage, meansfor opening said second valve to permit the hydrostatic pressure of theduid in the well bore to actuate said hydraulic means, a secondY sealedchamber in said tool body, a third passage in said tool body connectingsaid second chamber with said hydraulic means, a third valve in saidthird passage, and means connected to said second and third valves forsubsequently closing said second valve and then opening said third valveto permit the well iluid trapped in said hydraulic means by the closingof said second valve to enter said second chamber, thus per-v mittingsaid lirst valve to close and subsequently said 6. In combination, awire line, a tool body connected to the lower end of the wire line andadapted to be lowered into a well by said line, said body having spacedexpansible packers thereon,V a body of hydraulic uid inV said tool body,a conduit connecting said body of uid with the interior of said packers,said tool body having a sample chamber formed therein, a first passageconnecting the chamber with the exterior of the tool body at a pointbetween the packers, a rst valve in said rst passage for controlling theow of formation iiuid therethrough, hydraulic means operativelyconnectedV to said packers 9 and said iirst valve and adapted to beactuated by the hydrostatic pressure of the uid in the well to expandsaid packers and subsequently open said iirst valve, said hydraulicmeans comprising a low pressure piston adapted to be actuated by Welluid pressure, a high pressure piston connected to said low pressurepiston for actuation thereby, said high pressure piston being incommunication with said body of hydraulic iiuid whereby a higherpressure than existing in the well uid is created to expand the packersagainst the walls of the well bore, a second passage in said tool bodyproviding communication between said low pressure piston and theexterior of said tool body above said packers, a second valve forcontrolling the flow of well uid through said second passage, and meansfor opening said second valve to permit the hydrostatic pressure of thewell bore to actuate said hydraulic means.

7. An oil well formation iiuid tester comprising a tool body havingspaced expansible packers thereon, said tool body having a samplechamber formed therein, a iirst passage connecting the chamber with theexterior of the tool body at a point between the packers, a iirst valvein said iirst passage for controlling the iiow of formation uidtherethrough, hydraulic means operatively connected to said packers andsaid iirst valve and adapted to be actuated by the hydrostatic pressureof the uid in the well to expand said packers and subsequently open saidiirst valve, a second passage in said tool body providing communicationbetween said hydraulic means and the exterior of said tool body abovesaid packers, a second valve for controlling the flow of well uidthrough said second passage, means for opening said second valve topermit the hydrostatic pressure of the uid in the well bore to actuatesaid hydraulic means, said means for opening said second valve includinga detonatable charge in the tool body operable when detonated to opensaid second valve.

8. In combination, a wire line, a tool body connected to the lower endof the wire line and adapted to be lowered into a well by said line,said body having spaced expansible packers thereon, said tool bodyhaving a sample chamber formed therein, a iirst passage connecting thechamber with the exterior of the tool body at a point between thepackers, a iirst valve in said iirst passage for controlling the ow offormation uid therethrough, hydraulic means operatively connected tosaid packers and said rst valve and adapted to be actuated by thehydrostatic pressure of the uid in the well to expand said packers andsubsequently open said rst valve, a second passage in said tool bodyproviding communication between said hydraulic means and the exterior ofsaid tool body above said packers, a second valve for controlling the owof well iiuid through said second passage, means for opening said secondvalve to permit the hydrostatic pressure of the uid in the well bore toactuate said hydraulic means, said means for opening said second valveincluding a detonatable charge in the tool body operable when detonatedto open said second valve.

9. An oil well formation uid tester comprising a tool body having spacedexpansible packers thereon, said tool body having a sample chamberformed therein, a iirst passage connecting the chamber with the exteriorof the tool body at a-point between the packers, a iirst valve in saidrst passage for controlling the ow of formation uid therethrough,hydraulic means operatively connected to said packers and said iirstvalve and adapted to be actuated by the hydrostatic pressure of the uidin the well to expand said packers and subsequently open said iirstvalve, a second passage in said tool body providing communicationbetween said hydraulic means and the exterior of said tool body abovesaid packers, a second valve for controlling the ow of well uid throughsaid second passage, means for opening said second valve to permit thehydrostatic pressure of the uid in the well bore to actuate saidhydraulic means, a second sealed chamber in said tool body, said meansfor opening said second valve including a detonatable charge in the toolbody operable when detonated to open said second valve, a third passagein said tool body connecting said second chamber with said hydraulicmeans, a third valve in said third passage, and means connected to saidsecond and third valves for subsequently closing said second valveandthen opening said third valve 'to permit the well uidtrapped in saidhydraulic means by closing of said second valve to enter said chamber,thus permitting said iirst valve to close and subsequently said packersto collapse.

l0. An oil well formation fluid tester comprising a tool body havingspaced expansible packers thereon, said tool body having a samplechamber formed therein, a rst passage connecting the chamber with theexterior of the tool body at a point between the packers, a iirst valvein said iirst passage for controlling the ow of formation fluidtherethrough, hydraulic means operatively connect` ed to said packersand said iirst valve and adapted to be actuated by the hydrostaticpressure of the iiuid in the Well to expand said packers andsubsequently open said iirst valve, a second passage in said tool bodyproviding communication between said hydraulic means and the exterior ofsaid tool body above said packers, a second valve for controlling theflow of well fluid through said second passage, means for opening saidsecond valve to permit the hydrostatic pressure of the iluid in the Wellbore to actuate said hydraulic means, said means for opening said secondvalve including a detonatable charge in the tool body operable whendetonated to open said second valve, and a clock mechanism in ,said toolbody operable to detonate said charge after a predetermined interval oftime.

ll. In combination, a wire line, a tool body connected to the lower endof the wire line and adapted to be lowered into a well by said line,said body having spaced expansible packers thereon, said tool bodyhaving a sample chamber formed therein, a iirst passage connect ing thechamber with the 'exterior of the tool body at a point between thepackers, a iirst valve in said iirst passage for controlling the ow offormation uid therethrough, hydraulic means operatively connected tosaid packers and said iirst valve and adapted to be actuated by thehydrostatic pressure of the fluid in the well to expand said packers andsubsequently open said first valve, a second passage in said tool bodyproviding communication between said hydraulic means and the exterior ofsaid tool body above said packers, a second valve for controlhng theiiow of well fluid through said second passage, means for opening saidsecond'valve to permit'the hydrostatic pressure of the fluid in the wellbore to actuate said hydraulic means, said means for opening said secondvalve including a detonatable charge in the tool body operable whendetonated to open said secL ond valve, and a clock mechanism in saidtool body operable to detonate said charge after a predetermined n-vterval of time.

12. ln combination, a wire line, a tool body connected to the lower endof the wire line and adapted to be lowered into a well by 'said line,said body having spaced expansible packers thereon, said tool bodyhaving a sample chamber formed therein, a iirst passage connect# ing thechamber with the exterior of the tool body at a point between thepackers, a iirstvalve in said iirst passage for controlling the iiow offormation liuid therethrough,- hydraulic means operatively connected tosaid packers and said iirst valve and adapted to be actuated by thehydrostatic pressure of the fluid in the well to ex= pand said packersand subsequently open said iirst valve, a .second passage in said toolbody providing communication between said hydraulic means and theexterior of said tool body above said packers, a second valve forcontrolling the ow of well liuid through said second passage, means foropening said second valve to permit the hydrostatic pressure of thefluid in the well bore to actuate said hydraulic means, said means foropening said second valve including a detonatable charge in the ondvalve to enter said chamber, thus permitting said iirst valve to closeand subsequently said packers to collapse.

13. An oil well formation tluid tester comprising a tool body havingspaced expansible packers thereon, said tool body having a samplechamber formed therein, a iirst passage yconnecting the chamber with theexterior of the tool body at a point between the packers, a rst valve insaid rst passage for controlling the ow of formation fluid therethrough,hydraulic means operatively connected to said packers and said firstvalve and adapted to be actuated by the hydrostatic pressure of theliuid in the well to expand said packers and subsequently open saidlirst valve, a second passage in said tool body providing communicationbetween said hydraulic means andthe exterior of said tool bodyabove saidpackers, a second valve for controlling the ow of well uid through saidsecond passage, means for opening said second valve to permit thehydrostatic pressure of the uid in the well bore to actuate saidhydraulic means, and a uid by-pass passage in said body communicatingwith the exterior of the tool body at points above and below the upperand lower packers, respectively,whereby the weight of the column of weilfluid in the Wellris Vnot imposed on the packers when iset.

14. In combination, a wire line, a tool body connected to the lower endof the wire line and adapted to be lowered into the wellV by said line,said body having spaced expansible packers thereon, said tool bodyhaving a sample chamber formed therein, a rst passage connecting thechamber with the exterior of the tool body at a point between thepackers, a rst valve in said rst passage for controlling the ow offormation uid therethrough, hydraulic means operatively connected tosaid packers and said tirst valve and adapted to be actuated by thehydrostatic pressure of the liuid in the Well to expand said packers andsubsequently open said first valve, a second passage in said tool bodyproviding communication between said hydraulic means and the exterior ofsaid body above said packers, a second valve for controlling the dow ofwell :liuid through said second passage, means for opening said secondvalve to permit the hydrostatic pressure of the tluid inthe well bore toactuate said hydraulic means, and a uid by-pass passage in said bodycommunicating with the exterior of the tool body at points above andbelow the upper and lower packers, respectively, whereby the weight ofthe column of well fluid in the well is not imposed on the packers whenset.

l5. An oil well formation fluid tester comprising a tool body havingspaced expansible packers thereon, said tool body having a samplechamber Yformed therein, a first passage connecting the chamber with theexterior of the tool body at a point between the packers, atirst valvein said iirst passage for controlling the ow of formation fluidtherethrough, hydraulic means operatively connected to said packers andsaid first valve and adapted to be actuated by the hydrostatic pressureof the 12 V fluid in the well to expand said packers and subsequentlyopen said rst valve, a second passage in said tool body providingcommunication between said hydraulic means and the exterior of said toolbody above said packers, a

second valve for controlling the ilow of well iluid through said secondpassage, means for opening second valve to permit the hydrostaticpressure of the fluid in the well bore to actuate said hydraulic means,a-

uid by-pass passage in said body communicating with the exterior of thetool body at points above and below the upper and lower packers,respectively, whereby the weight of the column of well fluid in the wellis not imposed on the packers when set, a second sealed chamber in saidtool body, a third passage in said tool body connecting said secondchamber with said hydraulic means, a third valve in said third passage,and means connected to said second and third valves for subsequentlyclosing said second valve and then opening said third valve to permitthe well fluid trapped in said hydraulic means by closing of said secondvalve to .enter said chamber, thus permitting said first valve to closeand subsequently said packers to collapse.k

16. An oil well formation iiuid tester comprising a tool body havingspaced expansible packers thereon, said tool body having a samplechamber formed therein, a rst passage connecting the chamber with theexterior of the tool body at a point between the packers, a rst valve insaid first passage for controlling the flow of formation liuidtherethrough, hydraulic means operatively connected to said packers andsaid first valve and adapted to be actuated by the hydrostatic pressureof the duid in the well to expand said packers and subsequently opensaid lirst valve, a second passage in said tool body providingcommunication between said hydraulic means and the exterior of said toolbody above said packers, a second valve for controlling theV iiow ofwell uid through said second passage, means for opening said secondvalve to permit the hydrostatic pressure ofthe tluid in the well bore toactuate said hydraulic means, said means for opening saidsecond valveincluding a detonatable charge in the tool body operable when detonatedto open said second valve, a clock mechanism in said tool body operableto detonate said charge after a predetermined interval of time, a tluidby-pass passage in said body communicating with the exterior of the toolbody at points above and below the upper and lover packers,respectively, whereby the weight of the column of well uid in the wellis not imposed on the packers when set, a second sealed chamber in saidtool body, a third passage in said tool body connecting said secondchamber with said hydraulic means, a thirdvalve in said third passage,and means connected to said second and third valves for subsequentlyclosing said second valve and then opening said third valve to permitthe well huid trapped in said hydraulic means by closing of said secondvalve to enter said chamber, thus permitting said iirst valve to closeand subsequently said packers to collapse.

References Cited in the le of this patent UNITED STATES VPATENTS Y

